Condolences have poured into Washington and Jerusalaem from nations across the globe.

In Israel, the country was in mourning over the loss of Col. Ilan Ramon, the first Israeli to fly in space (Israel in mourning).

"The state of Israel and its citizens are as one in this difficult time," a statement from Israeli Prime Minister Ariel Sharon's office said.

European tributes

In Europe, Pope John Paul II led the words of tribute and prayers. The pope received the news with great sadness and prayed for the astronauts during services, a Vatican official told the Associated Press.

British Prime Minister Tony Blair was among several European leaders who wrote letters of condolence to U.S. President George W. Bush and Sharon.

A spokesman for Blair's office said he wrote to "express the government's sadness and offer his condolences after the death of the courageous astronauts."

European Union Commission President Romano Prodi told Italian news agencies the "enormous tragedy" had occurred "in the service of progress, science and in this case, we can really say humanity."

French President Jacques Chirac wrote: "In the name of the French people, forever a friend to the American people, I express to you the profound emotion and feeling of solidarity in the ordeal that all my compatriots are feeling."

In Belgium, the Minister for Scientific Research Charles Picque expressed regret at the "immense human tragedy."

German Chancellor Gerhard Schroeder paid tribute to the "courageous men and women" who died in the "terrible tragedy."

Italy's Premier Silvio Berlusconi said he was "deeply shaken by today's tragedy."

He added: "In the name of the Italian people and government, I express condolences and solidarity with the families of the victims and with the American people."

Russian President Vladimir Putin called Bush to express his condolences, the presidential press service said.

Putin said that U.S.-Russian cooperation in space exploration made the accident even more tragic for Russians.

Senior Palestinian negotiator Saeb Erakat said Palestinian Authority President Yasser Arafat sent a letter of condolence to Bush.

"He expressed his deepest condolences to President Bush and to the American people and to the families of the astronauts in this tragic explosion of the space shuttle Colombia," Erakat said.

In addition, "President Arafat expressed his condolences to the six American families and to the Israeli family for the loss of their loved ones in the explosion of the space shuttle Columbia," Erakat said.

Poignancy

In Asia, Indian Prime Minister Atal Behari Vajpayee sent Bush his sympathies.

"We mourn with you in this moment of grief. Our hearts go out to the bright young men and women who were on that spacecraft. For us in India, we felt that since one of them was an Indian-born woman it adds a special poignancy to the tragedy," Vajpayee said.

"The world has seen with admiration the U.S. spacecraft program. We hope that in the days to come it will reach new heights." (India mourns space heroine)

Chinese President Jiang Zemin also offered Bush his condolences, saying the government and people of China deeply regret the disaster, state-run Xinhua news agency reported.

Japan offered its condolences and aid after the shuttle disaster

"We pray for the souls of the astronauts who bravely contributed to the progress of the human race," Prime Minister Junichiro Koizumi said in a message sent to Bush.

"We offer our heartfelt condolences to the families of the astronauts and to the people of the United States," he said.

Japan's space agency said it was establishing a task force to gather information about the incident and would send experts to help if needed.

The National Space Development Agency of Japan said the shuttle's lost could impact on Japan's plans to construct a module on the International Space Station.

The March 1 launce of shuttle Atlantis, which was to have included a Japanese astronaut, looks likely to be delayed after NASA suspended all shuttle flights in the wake of the Columbia disaster.

'Loss to humankind'

In Australia, a spokesman said Prime Minister John Howard was shocked at the incident.

"On behalf of the Australian people he expressed his deepest sympathy to the families involved and to the American, Israeli and Indian people on the loss of their astronauts," the spokesman said.

Elsewhere, Canada paid tribute to Columbia's crew.

"The seven astronauts on board were accomplished women and men of great courage who put their extraordinary skills and knowledge to the service of humankind," Prime Minister Jean Chretien said in a statement.

"Each one was a hero. Their contribution to science and space exploration will never be forgotten."

The United State's southern neighbor Mexico "expressed its condolences to the government and people of the United States."

At the United Nations, Secretary-General Kofi Annan described the incident as a "loss to all humankind."

"Because the exploration of space knows no national boundaries, the loss of the Columbia is a loss to all humankind," Annan said.